If you use Illustrator as a Type design tool you have been warned.
If you alter kerning regularly CS will make a mess. Apparently the print engine has been changed. So your old files done in
10.3 of a month ago will not come-out the way they were designed.
And if your using Panther which it was designed to excel in (rubbish),
copy and paste text into any other program such as Mail or Word you cant edit it. Costumer support was no help.